Cloudflare and Private NetworkDNS Hosting and Security

As we move services SaaS and to the cloud and eventually have less of a need for Internal DNS and an internal DNS server, is there a way to setup an authoritative private DNS server in Cloudflare (for a .net internal domain), and restrict access/queries to it by IP network (so all requests must originate from within specified IP networks) so DNS info is private?

I can then have our internal gateway be a secondary DNS and set it to query the authoritative DNS server and answer queries as a backup.

I can’t think of any way Cloudflare DNS can do this. I’ve never seen any type of DNS request filtering. It’s all public, and everybody gets the same query results.